Synonym: attentive, lively, nimble, on the job, prompt, ready, watchful, dull, slow, torpid. Similar words: dealer, ruler, clerk, killer, gallery, clergy, hitler, bowler. Meaning: [ə'lɜːt] 
n. 1. condition of heightened watchfulness or preparation for action 2. a warning serves to make you more alert to danger 3. an automatic signal (usually a sound) warning of danger. v. warn or arouse to a sense of danger or call to a state of preparedness. adj. 1. very attentive or observant 2. mentally responsive 3. not unconscious; especially having become conscious 4. (usually followed by `to') showing acute awareness; mentally perceptive.
n. 1. condition of heightened watchfulness or preparation for action 2. a warning serves to make you more alert to danger 3. an automatic signal (usually a sound) warning of danger. v. warn or arouse to a sense of danger or call to a state of preparedness. adj. 1. very attentive or observant 2. mentally responsive 3. not unconscious; especially having become conscious 4. (usually followed by `to') showing acute awareness; mentally perceptive. 
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91. I felt stimulated - mentally alert, talkative and sociable.
92. Emergency services were put on alert.
93. He listens with an alert, humorless expression.
94. Schools need to be constantly alert to this problem.
95. The medicine can make it difficult to remain alert.
96. The alert began shortly after midnight.
97. Could she alert him to her danger?
98. Again they circled slowly, eyes locked, alert.
99. Their faces soot black, raccoon eyes grim, alert.
100. They blended together to form one flowing alert.
101. The National Health Service was put on red alert.
102. Minton was also alert to developments in contemporary art.
103. The men at the guns stayed alert.
104. Checks and balances required an alert and informed populace.
105. Report, page 11 Flu outbreak puts hospitals on alert.
106. Nevertheless, she is delightfully forthright, alert and amusing.
107. The Normans, that summer, began to mesh into the fabric of the new, alert life of the country.
108. Tot alarm wire alert FIRE chiefs yesterday warned parents to check the cables of baby alarms.
109. The girl's landlady had made a packed lunch from pork which is at the centre of a botulism alert.
110. Does it need 7,000 nuclear weapons on full alert, and three weapons laboratories?
111. His head came around, brown eyes alert as fitzAlan strode out of the alehouse, ducking his head to negotiate the doorway.
112. Note that while the dog's body remains still it is none the less alert and watchful, awaiting further instructions from its owner.
113. Slightly smiling, alert to the expressions on three faces, Oliver came out of the shack.
114. Their faces were alert and simple Like faces of little animals, small night lemurs caught in the flashlight.
115. It owes its second chance of life to an alert dock worker.
116. Coastguards ordered a full emergency alert as the vessel drifted away from the Amoco rig 120 miles east of Aberdeen.
117. His appearance follows a security alert in Oxford last night.
118. A sort of gauge with a dial that shifts from red alert to black alert ... to warn of fall-out.
119. The events which followed put the police force of a large northern town on full alert for a missing officer.
120. Too alert to sleep,(http://sentencedict.com/alert.html) I fill my notebook with sketches of the nubble under the quarter moon while Margaret naps.